Excessive sodium intake is regarded as a crucial factor related to developing and worsening of cardiovascular disease (CVD). However, epidemiological studies on this topic in patients with type 2 diabetes are sparse. We investigated the associations between sodium intake and CVD risk in Japanese patients with type 2 diabetes from the analysis of pooled data from two nation-wide prospective longitudinal studies. Data were analyzed on 2428 individuals whose dietary intake at baseline was assessed by the Food Frequency Questionnaire based on food groups. Primary outcome was the 6-year risk of a CVD event. Cox regression analyses estimated hazard ratios (HRs) for dietary intake adjusted for age, gender, body mass index, HbA1c, smoking, energy intake, and other confounders. Mean sodium intake in quartiles ranged from 2494 mg to 6166 mg/day and more than three-quarters of participants had sodium intake more than the recommended dietary allowance by American Diabetes Association (< 2300 mg/day). After adjustment for confounders, HRs for CVD in patients with sodium intake in the 2nd, 3rd, and 4th quartiles compared with sodium intake in the 1st quartile were analyzed, and no significant differences were shown between sodium intake and CVD [Q2: 0.77 (95%CI, 0.48-1.23); Q3: 1.03 (0.65-1.63); and Q4: 1.31 (0.80-2.14), trend p = 0.131]. Results of subgroup analysis according to age showed that patients aged 39 through 59 years in the higher quartiles of sodium intake compared with the 1st quartile had a significantly higher incidence of CVD [Q2: 1.37 (0.57-3.33); Q3: 1.68 (0.70-4.03); and Q4: 4.16 (1.63-10.58), trend p = 0.004]. However, no significant association between sodium intake and CVD in participants aged over 60 years. Findings indicated that high sodium intake is associated with elevated incidence of CVD in younger patients with type 2 diabetes.
C. Horikawa: None. H. Sone: Research Support; Self; Astellas Pharma Inc., Eisai Co., Ltd., Kyowa Kirin Co., Ltd., Novo Nordisk, Ono Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co. R. Aida: None. S. Tanaka: None. C. Kamada: None. Y. Yoshimura: None. R. Kodera: None. K. Fujihara: None. T. Moriya: None. A. Araki: None.
Japan Society for the Promotion of Science (19H04028)